Apparatus for pumping and mixing liquids



Jan. 4, 1938. F. c. METZGER APPARATUS FOR PUMPING AND MIXING LIQUIDS Filed March 16, 1956.

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Patented Jan. 4, 1938 UNITED STATES APPARATUS FOR P UMPING AND MIXING UIDS Francis 0. Metzger, Cleveland Heights, Ohio, asv lignor to General Electric Company, a corpov ration of New York Application March 16, 1936, Serial No. 68,984

My invention relates toapparatus-for pumping liquids and more particularly relates to apparatus for pumping and mixing corrosive liquids such as are used in etching the glass bulbs oi 6 electric lamps. Although rubber and other materials are not aii'ected by the corrosive liquid, it has been dimcult to utilize them fully on account of the pump construction, involving, as it did, a number of moving parts. I have devised a construction in which the rubber protective material may be readily incorporated. My pump comprises a tank into which the liquid flows by gravity from the supply tankand means 'for supplying compressed air to the first tank at intervals to force the liquid therein to the point desired. The parts of my pump are protected by rubberliners. By returning the unused liquid to the supply tank, the complete supply thereof is mixed. I

The principal object of my invention is to provide an apparatus for pumping corrosive liquids which is economical of construction and still, which affords satisfactory protection from the liquid. Another object o! my invention is to pro- 25 vide an apparatus for mixing as well as pumping corrosive liquids. Other objects of my invention will appear from the detailed description which follows of one species thereof and from the accompanying drawing.

The drawing is a side elevation of the liquid mixing and pumping apparatus of my invention. The corrosive liquid is contained within the tank l0 and is mixed by the turbulence result- King from the alternate withdrawing of a quan- 35 tity oi the liquid from the bottom and the pouring oi it back in the top. The liquid leaving the bottom of the tank It) flows by gravity through the pipe elbow H, the check valve l2, the flexible hose l3 and the pipe T l4 tothetank I5. This tank i5 is supported by the cable i4 and the counterweight H, the counterweight I! being slightly heavier than the tank ii. The cable 18 passes over the pulleys i8, H which are stationarily mounted through brackets 20 and, respectively. The tank i5 is held in position by the guide rods 22 and 23 which it engages slidably through the blocks 24, 25 and 26, 21 respectively. The rods 22 and 23 are mounted by means of the brackets 28, 29 and 30 which grip them and prevent any movement thereof.

When the weight of the tank 15 and the liquid therein beet-mes more than that of the counterweight l'i. the tank I5 moves downward until finger 3| engages roller 33. The roller 32 is attached to arm 38 which is pivotally attached to bracket 29 through pin 34 and to lever 35 through link 36. The arm :33is held in thisposition by the cable and the weight 38 which pull the arm 33 upward so that the roller 39 in the end of lever 35 rests against the projection 40 of bracket 29. As the tank l5 fills, the pressure on roller ,32 increases until when the tank is filled it finally becomes so great as to cause the arm 33 to swing down. This movement occurs very rapidly once the arm 33 begins to move as the mechanical advantage of the system changes until finally the cable 31 passes below the pin 34 whereupon the arm 33 and roller 32 are pulled down out of the way of finger 3!.

In this way suflicient force is produced to cause 1 adjustment ,of the two-way valve 4| which is connected to lever 35 through pin 42, block 43, rod 44 and lever 45. The pin 42 strikes the upper end of the slot in block 43 when the cable 31 is some distance below pin 34. The lever 35 turns about the pin 46 extending from bracket 28 and when in the down position rests against the extended portion-41 oi said bracket 29. The tank I 5 has moved during this interval until it rests on springs 48 and 49.

The pumping operation begins as the valve 4! is adjusted so that the compressed air of pipe 50 passes to pipe SI and hence through hose 52 to the tank l5. The air pressure on top of the liquid forces it. out the pipe T i4 through the branch connected to hose 5!, through pipe T 54, valve to the tank I0. Circulation of the liquid through the other branch of pipe T l4 and hose I3 is prevented by the check valve i2. When tank I! has been emptied, the counterweight pulls it upward and the finger 3| strikes roller 38 moving it into the up position. The valve 4| is turned by the movement of lever 35 so that it stops the flow of compressed air and opens the tank connection to the atmosphere. The liquid now flows into the tank l5 and the operating cycle described is repeated. The weight 56 attached to the cable 51 passing over the pulley 53 on the stem of the valve 4i counterbalances the weight of the lever 45, rod 44 and block 43 so that the valve'can be adjusted more easily. If it is desired to take some of the liquid from the tank ill, the valve 55 is closed and the liquid will be pumped out the other branch of pipe T 54 to pipe 59. Because of the construction of all parts, a rubber liner (not shown) may be used therewith to protect the apparatus from the damaging effect of corrosive .liquids.

ing the bottom openings of said tanks, a two-way.

valve connected to the top opening in the first tank, to a supply 01' compressed air and to the atmosphere, means mounted adjacent the first tank operated by the combined weight of said first tank and the liquid therein forturning said valve to one position so that the first tank is opened to the atmosphere and the liquid fiows by gravity from the second tank and into the first tank and to a second position so that the compressed air is admitted to said first tank and the liquid is forced out'the bottom opening therein, a second pipe connecting the bottom of the first tank and the top of the second tank and a check valve connected in said first pipe for, preventing the liquid from returning therethrough to the second tank and for causing the liquid to be forced through said second pipe to said second tank.

2. An apparatus for pumping and mixing liquids comprising a tank having openings at the top andbottom thereof, a second tank mounted above and adjacent to the first tank and having top and bottom openings therein, a pipe connecting the bottom openings; of said tanks, a twoway valve connecting the top opening in thefirst tank with "a supply of compressed air or with the atmosphere, means mounted adjacent the first tank and operated by the combined weight of said first tank and the liquid therein for turning said valve to one position so that the first tank is opened to the atmosphere and the liquid flows 40 by gravity irom the second tank and into the first tank and to a second position so that the compressed air is admitted to said first tank and the liquid is forced out the bottom opening therein, an outlet connected to the top opening of said second tank and having a valve therein, a second pipe connecting the bottom 01' the first tank with said outlet above the valve therein, and a check valve connected in said first pipe for preventing the liquid from returning therethrough to the second tank and for causing the liquid to be forced through said second pipe to said second tank or out through said outlet depending upon whether the valve therein is opened or closed.

3. An apparatus for pumping and mixing liquids comprising a vertically movable closed tank, a second stationary tank mounted higher than said movable tank, a conduit connecting the bottom oi said stationary tank with said movable tank to permit theliquid to flow by gravity from said stationary tank to said movable tank, a check valve in said conduit to prevent the iiow oi liquid back to said stationary tank through said conduit, meansactuated by the downward and upward movement of said movable tank due to the presence or absence oi liquid therein for causing the interior oi" said tank to be connected respectively with a compressed airsource or with the atmosphere, an outlet opening from the top of said stationary tank and having a valve therein, and a conduit connecting the movabletank with said outlet above said valve therein whereby when said movable tank is connected to said compressed air source the liquid therein is forced throughv said second-mentioned conduit to said stationary tank or out through said outlet depending upon whether the valve thereinis opened or closed.

FRANCIS C. METZGER. 

